Map of Mars' south pole by Herschel

Map of Mars' south pole by Herschel

The first map of Mars was drawn by William Herschel in 1783. Herschel drew Mars over several weeks, observing all longitudes eventually. The small south polar cap was visible in every drawing. He conceived the idea of arranging the full disk images like flower petals, using the polar cap as a fixed central point, so he could see the global distribution of dark markings. In this illustration, his map (labeled A) shows that pattern, with an overlay of circles indicating the individual views which made up his set of observations. In his original, each circle is labeled with the date of observation. Map B is one made by the Aeronautical Chart and Information Center in 1962 for NASA's Mars mission planning, reprojected to match the south polar projection of Herschel's map.
The shape of Sinus Meridiani and Sinus Sabaeus at left will be familiar to Mars viewers. The bulge above it is Syrtis Major, not as pointed as in the USAF map, and the triangle at the bottom is probably Lunae Lacus, or a confused combination of that and Margaritifer Sinus. The hook shape at the top is Thoth-Nepenthes.